Surfacing material for refractory ware



PAUL TT-E'IGB, OF LAWBENCE KANSA S, ASSItG-NOR 330 THE JEFFEBY-DEWITTCOMPANY, 01*? DETROIT, MICHIGAN, A CGBPQRATION 0h MAINE.

$URFACING MATERIAL FOR REFRACTDRY WARE.

Ho Drawing.

such as saggars, cranks, linings, and kiln.

furniture generally, that aroused in kilns and furnaces for supportingor containing ceramicware while being fired. The coating containing, myinvention prevents deleterious effects on the ceramic were when theceramic were is in contact with the refractory bodies, or Within therefractory bodies,

- or fired in the presence of the refractory bodies.

When ceramic ware is in contact with, or contained within the refractorybodies as in the case of saggars, etc., or in the presence of therefractory bodies when fired, the glaze covering the ceramic warewillnot be dulled or injured or discolored, if the refractory bodiescontain injurious ingredients that lituef va orize or asifv. The decomosition of the materials of the refractory bodies, or the liqueficationand. gasihcation, commonly occurs by reason of the low grade clays used,or by reason of the fluxes used, or by reason of characteristics ofthe/refractory material itself. These deleterious conditions develop andincrease by reason of the repeated high temperature changes to which therefractory bodies are subjected.

The protective coating embodying: my in vention will prevent the escapeof anydcstructive or injurious liquids or gases that may develop withinthe refractory bodies, or at or near the surface of the refractorybodies. since the protective coating will render the refractory bodiessubstantially gas tight so that ceramic ware may be fired Within or inthe presence of such refractory bodies vvithout destruction or injury ofthe glaze of the ceramic Ware. Also the protective coating may be formedso that the gases Application filed April 8, 1921. Serial Ho. 4:59,!75.

ceramic ware will be maintained in an atinosphere that will bebeneficial to glaze formation and Will improve the glaze appearance.

The protective material is of such a char actor that it will notvolatilize, and will prevent sticking of unglazed ceramic were to therefractory bodies, and also will prevent sticking of refractory bodiesthat are placed in contact with one another, aswhen saggars aresuper-imposed.

The invention has its particular value when used in connection withrefractory bodies formed of bonded particles ofsilicon carbide,particularly if the amount of the clay binder does not cover all of theparticles of the siliconcarbide. or, particularly, if the refractorysilicon carbide is formed of a relatively large proportion of fines.This is also true if a clay' binder, maturing at a 10W temperature isused, even though it is used in sufficient quantity to cover theparticles of silicon carbide. The silicon carbide will decompose when itis subjected to ahigh temperature, and form a discolorizing liquid whichdevelops at the surface of the refractory bodies in the form ofblisters. These give off a vapor or gas which discolor the glaze ofceramic bodies and thus injure or destroy the ceramic bodies that may befired in the presence of the refractory bodies. If the ceramic Ware isin contact with or is contained within the refractory bodies the illAll?

i into the liquid wash.

forming materials s'uclrcs clay, alumina, etc.

An ersinple of the composition of the sur fncing material is shown inthe following tsble, wherein tile percentages ere given by weight:

Various changes in the composition may be made such as:

Bell clsys 10% to 20% Kaolin -c 10% to 60% Morning. 15% to 85 'iiliematerials are ground together so to pose through at least a. twenty meshscreen, end suspended in a suitable medium,

prelersbly Water, so as to form t creamy slip. The material is appliedto the refractory bodies by painting with s brush, spra ing. or dippingthe refractory bodies The coated refractory bodies are then fired Itcone 11 or higher, when the material forms a vitreous or porous costing011th? refractory bodies depending on the ingredients of the compositionused. This is altered according to Whether the ceramic were is to beplaced in contact with the refrectory bodies, the temperature to whichthe were and the, loodies are to be subjected, and the viscosity or'lockof it to be pro duced at tile said temperature. Preferably the Con/tingshould have a fusion point exceedingcone 18;

If the composition is as given in t is ex ample, and i'ftlie temperatureoi the kiln is raised suiiic'cntly, the material will forni it coatingof siiiinienite over the surface of the refractory bodies. if desired,on organic binder may be incorporated in the wash to cause theadherence, to the refractory bodies until they have been fired. Also ifdesired fluxes may be added, but not exceeding 2%. The refractory bodiesare thus made gas tight, which prevents injurious gases escaping fromthe refractory bodies. It the efroctory bodies are in the form of conteine'rs, the surfacing material of the re.

fractory bodies retains the useful glaze gases arising from the ceramicwere located in the containers, and tllUSPj'GVQHtS the escape ofvolatile ingredients of the glaze of the ceramic were. This confinestire ceramic were in the atmosphere of the volatile ingradientsandincreeses the brilliency of the glaze formed on the ceramic bodies.

I claim:

LA refractory article for use in firing ceramic were to preventdiscolorisstion thereof, comprising a body containin sill con carbide,and a. protective costing free from silicon carbide formed thereon.

' 2. A refractory article for use in firing ceramic were to preventdiscolorizction thereof, comprising a body. containing sili con carbide,and s protective coating free from silicon carbide, and comprising a.refractory protective coating.

l. refractory article for use in firing ceramic were to preventdiscolorizzition thereof, comprising a body containing silicon carbide,and a. protective costing free from silicon carbide applied thereto, andcomprising 11 refractory glaze having a bi 1h viscosity.

4. A refractory article, the body of which contains silicon carbide,having a. surface coating free from silicon carbide end comprising arefractory glaze.

5. A refractory article, the body of which contains silicon carbide,having a. coating free from silicon carbide, and comprising-eglazehalving refractory properties preventing superficial dissociation of thesilicon can bide.

6. A refractory article, the body of which contains silicon ceroide,having a coating free from silicon carbide, comprising a.

refractory costing having a low alkali con that vitrifies at a.temperature above that st F which the ceremic were is tired.

10. A- refractory article, the body of which contains silicon carbide,and having s, costing free from silicon carbide and comprisingrefractory glaze with a. lesionv point exceeding cone 18.

11. A refractory article, the body of which conteins' silicon csrbide,and havin s. costing free from silicon carbide an comprising arefractory glaze containing not to exceed 2% of during constituents.

12. A refractory body formed of: ingredients that Willdisintegrste atrelatively low temperatures end to ice used in connec tion with firingceramic were at relatively high temperatures, and having '2. glazedcoating that will vitrify ct relatively high temperatures. y i

13. A refractory body formed of ingredients that will dieintegrete atrelatively low temperatures slid to be used in connection with firingceramic were at relatively containing-- sillimonile.

that volatilize at a relativel mute, and a coating containmg asillimgnmmic wnre, and havin a cbating containing ite .formingcomposition.

15. A refractory body used in firing ceramic'warc, and having'avitrified coating fori pre venting' the absorption of volatiliz- 22%;.ingitedient .---cf the: glaze of ceramic ies.

16: A refracidrij boils used in firing cca; sillimanibe formingcompo'sitionfor pi venting the absorgtioii of .vblatilizable in- Igradients of theg aze of ceramic bodies.

17. A refractory -body used in firing ceramic Ware, and having avitrified coating containing a sillimanite forming compgsitionforreventing the absorption of volatilizabie ingredients of the glaze ofvcmmic bodies.

In fiestimony whereof, I have hereunto signed my name to thisspecification.

mm; TEETO R.

